Thread rings or thread ring gauges are used for external thread control. Thread rings are produced in kits: go-on thread rings (PR) and no-go thread rings (NE). Thread ring gauges are produced to control various types of thread: metric thread, inch thread, pipe thread, and special thread. Depending on their diameter, the thread rings are classified as follows: rings with a full thread profile, with an incomplete thread profile, with a straight pipe thread profile, with an incomplete straight pipe thread profile, plain thread ring gauges and cylinder thread ring gauges of general purpose industrial grade. Rings are manufactured according to GOST standards or according to customer’s requirements.
| Name | Parameter | From | To | GOST standard |
|---|---|---|---|---|
| Thread rings with full thread profile | thread(М) | 6 | 42 | 17763-72 |
| Thread rings with incomplete thread profile | diameter(мм) | 6 | 42 | 17764-72 |
| Thread rings with full thread profile for straight pipe thread | diameter(") | 1/8 | 1 | 18929-73 |
| Thread rings with incomplete thread profile for straight pipe thread | diameter(") | 1/8 | 1 | 18930-73 |